Propeller.



No. 736,137.. PATENTED AUG. 11 1903.

A. G. J. H. MGINTOSH- PROPELLER.

APPLICATION FILED NOV. 24, 1902.

MODEL. 2 SHEEL-k-SHEET 1.

WITNESSES. IN VE/VTOH Wig/0 Janos Z/Z JZE YZZmI/i "ms Nana's PEIERS co.. PNO'fO-LITHO.. WASHINGTON, n. c

PATBNTED AUG. 11', 1903. A. c. J. H. momrosn.

PROPBLLER.

APPLICATION FILED NOV. 24, 1902.

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f'atented August 11, 1903.

PATENT FFICE. Y

AMOS O. J. H. MCINTOSH, EUREKA, CALIFORNIA.

PROPELLER.

SPECIFICATION forming part of Letters Patent No. 736,137, dated August 1 1, 1903. Application filed November 24, 1902., Serial No. 132,573. (ModeL) To all whom it may concern:

Be it known that I, AMOS O. J. H. MOINTOSH, a citizen of the United States, and a resident of Eureka, in the county of Humboldt and State of California, have invented a new and Improved Propeller, of which the following is a full, clear, andexact description.

This invention relates to a screw-propeller;

and it has for its purpose to provide a progrees or thereabout to the axis of the screw,

and from the hub I run the blade first outward toward the circumference and thence rearward, so that the after part of the blade lies essentially horizontal. The blade itself in its most efficient form has its root running diagonally across the hub and covering exactly one-half of the diameter thereof. The after or working face of'the blade is slightly flanged at its side edges, but at its outer or peripheral end it runs out plane. or idle face of the blade is slightly convex, and the blade is a true plane throughout its length. A propeller so constructed will act forcibly against the water at all points throughout its working face, owing to the fact that all parts of this working face lie at the most eifective angle to the axis of the propeller, and this in turn is due to the plane form of the blade and its position on the hub. I have found by experiment that when this blade is constructed of slightlyresilient metal it will in operation expand diametrically at its outer-portions not so much from centrifugal force as from the pitch of the blade and its horizontal disposition. The result of this is a steady increase in the diameter of the screw in exact proportion to the speed of the engine, thus gaining propelling power in the screw as the driving elfort of the engine increases.

This specification is an exact description of one form of my invention, While the claims define the actual scope thereof. y

Reference is to be had to the accompanying drawings, forming a part of this specification,

The forward in which similar characters of reference indicate corresponding parts in all the views.

Figure lis a side elevation of a propeller looking across the axis thereof and showing av two-bladed screw, said blades being projected, as shown, one directly upward and the other directly downward and the view being slightly in perspective. Fig. 2 is a view looking forward toward the rear or working faces of the blades and in a line coincident with the axis of the screw. Fig. 3 is a top View looking down on the screw, assuming the screw to be in the position shown in Fig. 1; and Figs. 4., 5, 6, and 7 are cross-sections taken through one of the blades on the lines 4 4, 5 5, 6 6, and 7 7 in Fig. 2 to show the form of the blade.

a indicates the hub of the propeller, which is here shown to be cylindrical in form.

b indicates the blades, which are joined to the hub, according to the construction here illustrated, at oppositesides, the root of the blade passing diagonally across the hub at an angle of forty-five degrees and said root extending exactly one-half around the diameter of the hub. The blades curve outward and rearward, so that theirouter portions lie essentially horizontal. (See Fig. 1.) The said blades are absolutely flat or plane-that is to say, there is no spiral curve, the pitch being secured wholly by the position of the blade on the hub and the outer part of the blade lying exactly in the same plane as the root thereof. (See Fig. 3.) As shown in Fig. 4, the blade has a slightly-convex forward or idle face I), and from the side edges of the working face flanges 6 project, these flanges giving the working faces of the blades a somewhat curved form. Said flanges terminate at the end of the side edges, leaving the end edge of each blade plane, as illustrated at the point b in Fig. 3. This wheel in r0- tating from left to right will present the working faces of the blades at every point throughout the area thereof to the water at the exact angle to which the blade is set, the propelling action being present directly adjacent to the hub as well as at the outer extremities of the blades. The water striking the working face of the blade between the flanges b is confined by said flanges and is thrown out in acompact form from the ends b of the blades, these ends being devoid of flanges, so as to provide a clear passage for the water. The result of this construction is that the whole surface of the blade exerts a propelling eflort and that the water is not swirled tangentially from the propeller, but is caused to pass in a compact column directly rearward from and in exact line with the propeller. Further, owing to the inclination of the blades and to their form, as described, as the screw turns at a relatively high speed the blades being constructed of slightly-resilient material are forced outward, thus in- 1. A propeller, comprising a hub, and

blades of slightly-resilient material, extending from the hub with their roots passing diagonally across the hub at an angle of about forty-five degrees to the same and at right angles to one another, said blades being curved outwardly and rearwardly and having their outer portions lying in the same plane with the roots thereof, each blade having on its side edges flanges projecting in direction of the working face thereof and terminating at the outer ends of said side edges, substantially as herein shown and described.

2. A propeller, comprising a hub, and two blades, said blades being each essentially a true plane, and set on the opposite sides of the hub at an angle thereto and at right angles to one another, and said blades also being directed outward and rearward so that their outer portions lie approaching parallelism with the axis of the propeller, said blades having rearwardly-directed flanges on their working faces, said flanges terminating at the outer ends of the blades, leaving the same open and unobstructed, for the purpose specified.

3. A screw-propeller, having a hub, and two blades thereon the root of each of which passes diagonally across the hub around approxim ately on e-half the circumference thereof, said blades being of'slightly-resilient material and projected outward and rearward from the hub so that their outer portions approach parallelism with the axis of the propeller.

4. A screw-propeller having a hub, and two blades thereon, the root of each of which passes diagonally across the hub around approximately one-half the circumference thereof and at right angles to one another, said blades being of slightlyresilient material and projected outward and rearward from the hub so that their outer portions approach parallelism with the axis of the propeller, and the said blades being flat from root to end and having flanges projecting from the side edges, said flanges extending in direction of the working faces of the blades.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

AMOS C. J. H. MOINTOSH.

Witnesses:

Y O. F. D'AIL, J. H. HODGE. 

